Stent & Stent Graft Testing Services

Stent testing is an important step in the preclinical validation process to assess compliance with standards and regulatory requirements. Element’s cardiovascular device experts offer a comprehensive suite of stent testing services including pulsatile durability, axial fatigue, bending and torsion, inspections, and custom test methods.

Endovascular devices such as stents and stent-grafts are implanted through minimally-invasive procedures to address a vessel blockage and restore blood flow. From drug-eluting and bioresorbable stents to vascular grafts, our experts test to the latest standards for a variety of clinical indications and anatomical locations.

Our stent and graft testing expertise allows us to evaluate the devices with a range of testing and inspection methods to determine dimensional attributes, displacement and dislodgement force, tensile and bend strength, radial force measurements, and more.

Stent testing services

Pulsatile durability testing - ASTM F2477, ISO 25539-1, ISO 25539-2, ISO 7198

During pulsatile fatigue, Element tests devices in mock vessels mounted to astent/graft tester, and subjects them to cyclical pressure pulses. The pulses create a dynamic radial strain in the mock vessel to simulate strains the device will experience in vivo.

In ourPulsatile Durability Testing of Complex Intravascular Devicesarticle, we guide you through a step by step overview of pulsatile durability testing.

Axial fatigue testing - ASTM F2942, ISO 25539-1 and ISO 25539-2

Axial fatigue testing may be used in tension or compression to mimic physiological loading conditions. Two key axial fatigue tests are crush resistance and S/N curve generation.

Crush resistance testing: We use crush resistance quasi-static tests radially or along the length of a stent to measure the stent’s ability to resist permanent deformation or cyclic fatigue to mimic 10 years of implantation. This test configuration is particularly useful in fatigue to study the impact of overlapping vessel interactions.

S/N curve generation: Our experts outline S/N fatigue testing in our articleTips for Medical Device Fatigue Testing. Load monitoring can be added to ensure that the specimen sees the desired load throughout the test and to detect specimen failures.

Bending and torsion durability testing - ASTM F2942 and ISO 25539-2

These tests are applicable when the device’s clinical use would result in bending or torsional loading such as peripheral stent applications, especially superficial femoral artery (SFA) indications that experience additional loading caused by natural gait motion, running, sitting, and standing.

We have developed awide variety of bend fixturesto accommodate bend tests such as pure bending, cantilevered, combined pure and cantilevered, constant radius, compression and shear-induced bending.

Torsion fatigue testing – ASTM F2942, ISO 25539-1, and ISO 25539-2

Element’s fixtures and test instruments can apply cyclical torsion loading to simulate a wide variety of clinical uses and anatomical locations, mounted directly on a test fixture or inside mock vessels and then secured on a test fixture. Multi-axial loading fixtures and instruments that apply tension/compression, bending and torsion simultaneously are also available.

Our article onMedical Device Torsion Testingdescribes torsional loading of peripheral stents.

Stent graft testing services

Vascular graft tests – ISO 7198

In addition to axial, torsional and pulsatile durability testing, there are several additional tests we offer for vascular grafts per ISO 7198 to characterize the following properties:

• 纵向抗拉强度在其管形式
• Circumferential tensile strength in its tubular form
• Pressurized burst strength in its tubular form
• Diaphragm pressurized burst strength and probe burst strength of graft in flat form
• Strength after repeated puncture with dialysis needles
• Suture retention strength
• Dynamic radial compliance

Inspection methods

Inspections are a key component of stent durability testing and are routinely performed before, during and after fatigue tests. Some inspections require device removal from the tester, such as microscopy, other methods require pausing the test, such as endoscopy, while methods such as high-speed video and stroboscopes are useful while a test is running.

The main inspection methods we employ during stent fatigue testing include:

• Visual
• Digital microscopy
• Endoscopes
• High-speed video
• Strobe light
• Media sampling for nickel ion release and particulate testing

For more information about our stent and stent graft testing services, or to request a quote, contact ourcardiovascular device testingexperts today.